Supraglottic Airway Devices — EMT / Paramedic

Objective. Students will insert a supraglottic airway device (including laryngeal mask airway and King LT or equivalent, per program equipment) into an adult airway manikin, confirm placement, and identify clinical situations in which a supraglottic device is preferred over endotracheal intubation.

What Are Supraglottic Airway Devices?

Supraglottic airway devices (SGAs) are airway adjuncts that are inserted into the oropharynx or hypopharynx and sit above (supra) the glottic opening. Unlike an endotracheal tube (ETT), which passes through the vocal cords into the trachea, an SGA creates a seal around or near the laryngeal inlet without entering the trachea. This design makes insertion faster to learn, faster to perform, and less technically demanding than endotracheal intubation — advantages that matter greatly in the prehospital setting.

Common SGA types used in EMS include the Laryngeal Mask Airway (LMA), the King LT (Laryngeal Tube), and the i-gel. Each works by a slightly different mechanism, but all allow ventilation via a bag-valve mask (BVM) without direct visualization of the cords.

How Each Device Works

Laryngeal Mask Airway (LMA): The LMA has an elliptical mask at its distal end. When inserted and inflated, the mask seals around the laryngeal inlet, allowing positive-pressure ventilation. It does not protect against aspiration as completely as a cuffed ETT. Standard LMAs come in numbered sizes based on patient weight.

King LT (Laryngeal Tube): The King LT is a dual-lumen, dual-cuff tube. The distal cuff seals the esophagus; the proximal cuff seals the oropharynx. Ventilation occurs through the port between the two cuffs, which sits at the level of the larynx. Both cuffs are inflated with a single syringe through one inflation port, with the volume determined by the color-coded size of the device. Sizes are selected based on patient height.

i-gel: The i-gel uses a soft, non-inflatable thermoplastic gel cuff that conforms to the perilaryngeal anatomy without active inflation. There are no cuff inflation steps, which simplifies insertion. Size is selected by patient weight.

Insertion Technique (General Sequence)

Although specific steps vary by device, the general sequence for SGA insertion is:

1. Select the correct size using the manufacturer's size chart (weight or height depending on device).

2. Prepare the device — lubricate the cuff or distal tip with water-soluble lubricant; for cuff-based devices, fully deflate the cuff before insertion.

3. Position the patient — sniffing position (slight head extension, neck flexion) or neutral position if spinal precautions are needed.

4. Insert the device — follow the natural curve of the airway; advance until resistance is felt or the manufacturer's depth marking is reached.

5. Inflate the cuff — inject the volume specified for that device size (King LT and LMA only; not applicable for i-gel).

6. Attach BVM and ventilate — deliver a breath while watching for bilateral chest rise.

7. Confirm placement — auscultate bilateral breath sounds in the midaxillary lines and absence of epigastric sounds. Use waveform capnography if available, as it is the gold standard for confirming ventilation.

8. Secure the device and continue monitoring.

When to Choose a Supraglottic Device Over Endotracheal Intubation

SGAs are generally preferred or indicated when:

Endotracheal intubation has failed or is not feasible (difficult airway anatomy, inadequate access).
Cardiac arrest management where minimizing interruptions to chest compressions is critical — SGAs can be inserted without pausing compressions.
Provider skill level or training does not include or maintain ETI proficiency.
Scene time must be minimized and securing a definitive airway in the field would cause harmful delay.
Patient has no gag reflex (deeply unconscious) — SGAs require an absent gag reflex for toleration.

SGAs are generally not preferred when: the patient has an intact gag reflex; there is a known or suspected airway obstruction below the glottis; the patient requires very high ventilation pressures (e.g., severe bronchospasm) that may exceed the device's seal pressure; or local protocol mandates ETI as the primary advanced airway.

Safety and Scope-of-Practice Considerations

SGAs are within the scope of practice for EMTs in many states for approved devices (verify your state's protocols).
Paramedics are expected to be competent with SGAs as a primary airway option and as a rescue airway after failed intubation.
Always follow local and medical-director-approved protocols for device selection and maximum insertion attempts.
A misplaced or dislodged SGA can result in inadequate ventilation or gastric insufflation — continuous monitoring with capnography and frequent reassessment are mandatory.
Document device type, size, cuff volume used, confirmation method, and patient response.
If at any point ventilation is inadequate, remove the SGA, ventilate with BVM and oral airway, and reattempt with the same or a different device.

Key Monitoring Point

Waveform capnography provides continuous, quantitative confirmation that ventilation is occurring. A flat waveform after SGA insertion means either the device is misplaced, the airway is obstructed, or the patient has no cardiac output — each requiring immediate action. Never rely on chest rise alone as the sole confirmation method.

Key terms8

Supraglottic airway (SGA)Any airway device that is positioned above the glottis to facilitate ventilation without passing through the vocal cords.

Laryngeal Mask Airway (LMA)A supraglottic device with an inflatable elliptical mask that seals around the laryngeal inlet, sized by patient weight.

King LT (Laryngeal Tube)A dual-cuff supraglottic device that seals the esophagus distally and the oropharynx proximally, with ventilation occurring between the cuffs; sized by patient height.

i-gelA supraglottic airway that uses a non-inflatable thermoplastic gel cuff to conform to perilaryngeal anatomy, eliminating active cuff inflation steps.

Waveform capnographyContinuous graphical monitoring of exhaled carbon dioxide, considered the gold standard for confirming ventilation and device placement.

Cuff inflation volumeThe specific volume of air injected into an SGA cuff to achieve an adequate seal, determined by device size and manufacturer specifications.

Rescue airwayA backup airway technique or device used when the primary airway method (such as endotracheal intubation) has failed or is not possible.

Epigastric auscultationListening over the upper abdomen during ventilation to detect gurgling sounds that indicate esophageal or gastric placement rather than tracheal/laryngeal ventilation.

In class: Device orientation and comparison: students examine available supraglottic devices side by side, review manufacturer insertion guides, and complete a comparison chart listing device type, cuff inflation steps, size-selection method, and contraindications for each. · Insertion lab: each student inserts each available supraglottic device into an adult intubation manikin, inflates cuffs per device specifications, attaches BVM, delivers ventilations, and confirms bilateral chest rise and absence of epigastric sounds. · Scenario-based decision exercise: instructor presents four written patient scenarios; students decide whether a supraglottic device or endotracheal tube is preferred, defend their choice in writing, and reference current national EMS protocol guidance.
Materials: Supraglottic airway devices (LMA and King LT or i-gel as available), intubation manikins, cuff inflation syringes, BVM units, stethoscopes, device comparison worksheet, manufacturer instruction guides
Check: Instructor-evaluated insertion checklist: student inserts assigned supraglottic device in correct sequence with no critical errors (correct size selection, full cuff inflation, confirmed placement by auscultation); pass requires zero critical errors.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.